Sometime in the early ninth century, the scholar-official Liu Yuxi (772–842) became ill while serving in southwestern China. He was afflicted with scorching pain, a sign of “obstructed flows.” Following a friend’s advice, Liu went to see a local doctor, who, upon examining him, blamed his unhealthy lifestyle. The doctor gave him a prescription but warned, “The medicine possesses du 毒 (toxicity or potency), so you must stop taking it once you are cured. Taking too much will injure your body. So take only a small dose.” The medicine worked: after ten days, Liu’s discomforts all vanished; within a month, he had fully recovered. Delighted, Liu ignored the doctor’s warning and continued to take the medicine, hoping to further enhance his vigor. But five days later, a numbing sensation spread throughout his body. Realizing his mistake, Liu rushed back to the doctor, who, of course, reprimanded him. The doctor then prescribed an antidote, and he was saved.
Liu recounts this episode in a short essay titled “Inspecting Medicines” (Jianyao).1 A figure known for his literary talent, Liu, like many of his fellow literati during the Tang dynasty (618–907), was also keenly interested in medicine, collecting useful formulas and sharing them with his coterie to spread the knowledge of healing.2 In this story, he reveals several key issues of classical Chinese medicine: the experience of sickness, the influence of lifestyle on health, and the trust between patients and doctors. Yet the most telling feature of the tale is the doctor’s prescription of a toxic medicine to cure Liu’s illness. How could a poison heal? And if poisons healed, what exactly was a medicine?
“Among the myriad things in the world,” the famous seventh-century physician Sun Simiao declared, “there is nothing that cannot be a medicine.”3 There was, in other words, no essential difference between medicines and nonmedicines; in the right context, anything could be a drug. And indeed, the Chinese pharmacy was vast, containing not just plants but also minerals, animal-derived materials, and foods. The celebrated sixteenth-century pharmacological treatise Systematic Materia Medica (Bencao gangmu), for example, included close to 1,900 entries using substances as wide-ranging as water, dirt, textiles, and even human excrement.4 Chinese pharmacology was thus at its core an exploration of the entire material world seen through the lens of therapeutics.
In this all-encompassing pharmacy, poisons loomed large. This might seem surprising given that today Chinese herbal remedies are widely imagined to be natural, mild, and safe, especially in comparison with the synthetic drugs of modern biomedicine, which are often perceived as artificial, exceedingly strong, and with therapeutic effects inseparable from dangerous side effects. Another familiar dichotomy contrasts the holistic approach of Chinese healing that seeks to restore the harmony of the body with the reductionist methods of biomedicine that eradicate specific diseases.5 Neither of these perceptions survives scrutiny: Chinese pharmacy has, over its long history, featured a rich miscellany of medicinal therapies that target diverse disorders. There were certainly mild treatments, such as food therapy, that aimed to balance the body and recover its resonance with the cosmos.6 Equally important but less examined is the tradition of harnessing toxic drugs that would forcefully destroy or expel pathogenic entities. In fact, Chinese doctors regularly relied on substances that they themselves recognized as possessing du. Aconite (fuzi), for example, a highly toxic herb grown in southwestern China, was one of the most frequently prescribed drugs in classical Chinese medicine. Conceptually, writers on pharmacy identified du as the key index for the classification of medicines. The foundational works of materia medica thus grouped drugs in a three-tiered hierarchy based on their toxicity, and revealingly placed most of the powerful drugs used in curing sickness in the most-toxic tier. Medicinal therapy in China, then, was inconceivable without poisons.
Moreover, classical Chinese pharmacy aimed at more than curing sickness; many substances in the least-toxic tier of the drug hierarchy promised to facilitate the cultivation of long life. Alongside its concern with treating illness, Chinese pharmacology was shaped by the goal of transforming the body into higher states of being and achieving longevity. This program of life enhancement involved a purification of the body that cleared its noxious burdens, leading it to ascend to various levels of sublime existence that correlated to one’s life span: the higher one reached, the longer one would live. The highest attainment, as expected, was immortality. Medicine in China thus developed through the interaction of two related but distinct enterprises: the fight against sickness and the quest for ever-enhanced vitality.
Most of the drugs assigned for this second goal were mild and therefore could be consumed regularly to strengthen the body. Yet this group also included a significant number of toxic substances, especially minerals, such as cinnabar, arsenic, and sulfur. The robustness of these minerals, many believed, could be readily transferred to the body, making it resistant to decay. Yet a dilemma naturally arose: while the ingestion of these powerful drugs was thought to transform the body and prolong life, their toxicity often precipitated the quick demise of many fervent users. Importantly, the violent sensations induced by such drugs elicited diverse interpretations that either justified or contested the consumption of these puissant medicines.
Figure I.1 illustrates these two dimensions of the use of poisons in premodern China. In this diagram, any position inside the cone represents a state of the body. The center of the circle at the bottom of the cone refers to a healthy body. Any deviation from this center refers to a state of sickness, with intelligent use of poisons offering the possibility of restoring the body to health. In addition to maintaining a healthy body devoid of illness, classical Chinese medicine strove for a higher goal of elevating the body to a “healthier” state, sometimes aided by toxic minerals. This elevated, “lighter” state of the body was less susceptible to sickness, as indicated by the smaller size of the plane. The ultimate objective was to raise the body to the tip of the cone, where there could be no possibility of becoming ill. This, of course, meant immortality. Poisons in classical Chinese pharmacy acted on a continuum from the elimination of sickness to the enhancement of life, and ultimately the escape from death.
The History of Medicines in China and Beyond
Over recent decades, the study of materiality and material culture has gained momentum in the history of science and beyond. Rather than just adopting a social constructivist approach, scholars have become increasingly sensitive to the material dimensions of the subjects they examine—be it a scientific instrument, a specimen, or an object of daily use. This methodological shift by no means reduces historical inquiries to material determinism; rather, it acknowledges the physical constraints of things and underscores their open-ended potential. Material objects thus offer a unique lens through which one can acquire a sophisticated understanding of the society and culture in which they acted.7
This material turn in recent scholarship provides useful insight for the study of the history of Chinese medicine. Early inquiries focused on the theoretical foundations of the healing system and its unique practices, such as acupuncture, interest in which has been influenced by its rising status in contemporary society.8 Yet the history of Chinese medicine cannot ignore the history of Chinese medicines; the rich variety of medicinal substances in Chinese pharmacy constituted a vital part of the healing repertoire. What is striking about these drugs is their fluid materiality; that is, each of them was viewed not as fixed matter with a definite action but as a mutable substance that could undergo manifold transformations and elicit diverse effects.9 Although du is the standard Chinese word for poison today, its core meaning in the past was potency—the power not just to harm as a poison but also to cure as a medicine. This duality was central to classical Chinese pharmacy: no material essence marked off poisons from medicines; the effect of any given substance—whether it healed as a medicine, or sickened or killed as a poison, or altered a person in myriad other ways—varied greatly according to the way in which it was prepared and deployed, the bodily sensation it induced, and its assigned value in society. In short, when we ponder what was a medicine, context mattered.
No example illuminates this transformative capacity of medicines better than the regular use of poisons. Yet, despite their importance in Chinese pharmacy, they have largely escaped the attention of medical historians. One notable exception is Frédéric Obringer’s L’aconit et l’orpiment: Drogues et poisons en Chine ancienne et médiévale (Aconite and orpiment: Drugs and poisons in ancient and medieval China), the most extensive study of the topic to date. The monograph offers a detailed pharmacological analysis of poisons in China from antiquity to the eleventh century, with a focus on the medical understandings of poisons and the pharmaceutical principles underlying their use, but to the exclusion of situating these powerful substances in a broader context.10 Several other studies have looked beyond the medical realm, exploring poisons in the social, political, and religious culture of premodern China, yet these investigations tend to be brief and episodic, and to focus on the use of poisons for nefarious purposes.11
The therapeutic use of poisons was not unique to China. By examining the social history of poisons in colonial India, the historian of medicine David Arnold has demonstrated the complex interplay between European toxicological knowledge and India’s “poison culture,” which stimulated colonial scholarship and triggered new regulations of these dangerous materials.12 An important aspect of this culture was the medical use of poisons, which can be traced back to Ayurvedic healing in the premodern era. Although this is not the focus of his study, Arnold muses that “[p]erhaps even among Asian societies, only China, with its ancient use of aconites and orpiment, its Western missionary condemnation of toxic remedies and its recent wholesale descent into industrial pollution, has a comparable tale to tell.”13 The history of poisons in China has yet to be written. By probing the roots of this history in Chinese culture, Healing with Poisons seeks to enhance our understanding of the traditional value of poisons in Asia.14
There are comparatively more studies of poisons and poisoning in the European context, particularly focusing on their danger and harmful effects.15 It is useful to recall, however, that the Greek term pharmakon, from which the English word “pharmacology” derives, meant both remedy and poison, among other things.16 This paradoxical sense of drugs in early Western medicine shares much in common with the ancient meaning of du in China. Small wonder that the therapeutic use of poisons figured prominently in ancient Greek pharmacy. For example, Dioscorides’s De Materia Medica (first century), a foundational text in the history of Western pharmacology, contains more than sixty toxic drugs, such as opium poppy, mandrake, and hemlock, that were harnessed to treat diverse illnesses.17 Analogous to the Chinese case, the use of poisons as curative agents persisted throughout European history.18 Yet, beginning in the first century, a group of highly toxic substances in Greek pharmacy gradually moved out of the pharmakon continuum and were deemed to be absolute poisons without medicinal value. As the historian of medicine Frederick Gibbs has shown, this separation became more pronounced in late medieval Europe when physicians increasingly perceived poisons as ontologically distinct substances from medicines, which paved the way for the rise of toxicology in the early modern period.19
The concept of absolute poison, by contrast, never arose in premodern China. The use of toxic substances had constituted the core of Chinese pharmacy since its inception, and it remained so throughout the imperial era.20 No example better illustrates this divergence than the distinct fates of aconite in Greek and Chinese pharmacies. In De Materia Medica, aconite, also called wolfsbane, is described only as a poison to kill wolves, without any curative value. The Greek physician offers treatment for accidental aconite poisoning no less than seventeen times in his text, suggesting that he included the toxic plant simply to warn against its use.21 But in China, aconite (fuzi) was highly valued for its therapeutic power, and even hailed as “the lord of the hundred drugs.”22 This does not mean that there was no knowledge of the danger of poisons in China. Quite the opposite: we find abundant discussion of poison detection and treatment in classical Chinese pharmacy. Yet unlike the study of absolute poisons as substances fundamentally different from medicines in medieval Europe, the understanding of poisons remained an integral part of pharmacological knowledge in premodern China. This striking divergence of European and Chinese pharmacy likely derived from their distinct therapeutic rationales. If European physicians considered toxicity to be the cause of unpleasant side effects, Chinese healers deemed it to be the very source of curative power. In other words, European medicine prescribed poisons in spite of their toxicity; Chinese medicine, because of it.23
Medicines in Medieval China
A periodization that has been influential in the existing literature identifies three pivotal turning points in the history of Chinese medicine: the crystallization of medical theories during the Han dynasty (206 BCE–220 CE), the integration of doctrinal learning and empirical knowledge during the Song dynasty (960–1279), and the reinvention of Chinese medicine in the face of modern biomedicine in the nineteenth and twentieth centuries.24 Accordingly, these crucial moments have been studied in detail. With respect to the premodern period, scholars have extensively investigated the origins of Chinese medicine in the Han dynasty, epitomized by the formation of the foundational theoretical treatise The Yellow Emperor’s Inner Classic (Huangdi neijing).25 Other studies have focused on the transformation of medicine during the Song dynasty, examining the emergence of new medical theories, the explosion of medical writings facilitated by printing, the state’s effort to establish and disseminate medical canons, and the literati’s heightened interest in medicine.26 But what about the long period between the Han and Song dynasties, which is the focus of this book?
The medieval period in China starts with the collapse of the Han dynasty, followed by three centuries of political disunity, often called the Era of Division (220–589).27 From the early fourth century, various nomadic peoples from northern and central Asia occupied the north, while a succession of regimes established by the Han people ruled the south.28 Despite its political turbulence, the period witnessed a flourishing of literature, religion, and medicine. Medical writings were chiefly produced by individual healers and transmitted within powerful clans, reflecting the hereditary nature of medicine at the time.29 The situation changed in the seventh century, when the unified Sui (581–618) and Tang (618–907) empires, with Chang’an (present-day Xi’an) as their political center, established new institutions, promulgated legal codes, and commissioned authoritative texts to standardize medical knowledge and achieve effective rule. This favorable environment fostered the production of a collection of medical texts that proved influential in Chinese medical history.30 After the middle of the eighth century, the Tang state was substantially weakened by the devastating An Lushan Rebellion (755–63), which led to the decline of the central authority and the rise of local powers. As a result, the main agency producing medical knowledge shifted from the state to scholar-officials, who became interested in both the practical use of medicine and its allegorical value in political persuasion.
Despite its significance in the history of Chinese medicine, the period stretching from the third to the tenth century has been largely overlooked by medical historians, especially in English-language scholarship.31 More extensive studies on the medical features of this period have been conducted in Chinese, Japanese, and French scholarship, all of which have informed the writing of this book. In particular, Fan Ka-wai has made a major contribution to our understanding of the medical ideas and practices of this period. In a series of essays, he identifies the changing landscape of medicine from the Era of Division to the Tang dynasty and explores a wide range of issues, situating key medical features in the political, institutional, and literary culture of the time.32 Other researchers have focused on more specific topics, including the systemization of medical canons, religious healing, women’s medicine, and the construction of medical identity.33 Moreover, scholars have also performed in-depth analysis of a collection of medical manuscripts from Dunhuang and Turfan that offers key insights into the miscellany of healing practice in medieval society and the vibrant exchange of medical knowledge across Eurasia.34
What is particularly important about this period in the medical history of China is the growth of pharmacology. Although the roots of drug therapy can be traced back to the Han period, as exemplified by the foundational The Divine Farmer’s Classic of Materia Medica (Shennong bencao jing) and the excavated medical manuscripts from Mawangdui,35 its major outlines took shape in the following centuries, which saw the rapid expansion of pharmacy, the spread of pharmaceutical knowledge through society, and, especially relevant to this study, the enhanced understanding of toxic medicines. Two watershed moments warrant our attention as transformative for the therapeutic use of poisons.36 The first is the fifth century. Building on ancient classics, physicians and pharmacological compilers started to systematize knowledge of drugs by specifying the du status of each medicine and providing guidelines on how to prepare and employ drugs. This moment also witnessed increased pharmaceutical specialization, with different groups of actors engaged in harvesting, processing, selling, and prescribing drugs. The second is the seventh century, when the Sui and Tang states played an active role in creating new institutions and producing authoritative texts to regulate the use of poisons and standardize medical knowledge. Sun Simiao, one of the most celebrated physicians in Chinese history, also emerged in this century. Hailed as “the King of Medicines,” he integrated state-produced knowledge of drugs into his writings and relied on personal experience to affirm the efficacy of his formulas. By scrutinizing these two crucial moments in the history of Chinese pharmacology, Healing with Poisons seeks to unpack the rich culture of drugs in medieval China.
Furthermore, this book situates the study of drugs within the broader context of Chinese political history. A series of social, economic, and intellectual changes took place from the eighth to the twelfth century that profoundly transformed Chinese society. Often called “the Tang-Song transition,” these changes include, among others, the rise of meritocracy facilitated by the civil service examination system, the emergence of neo-Confucianism, the development of woodblock printing, and the consciousness of nationalism among literate elites.37 The transformation of the social order was so significant that some scholars have considered the eleventh century as the start of the modern era in China.38
In medical history, what is particularly salient in the new era is the state’s active engagement in medicine. The court of the Northern Song (960–1127) took advantage of printing technology to standardize and promulgate medical knowledge to achieve effective governance, an effort seen again only in the twentieth century, when the state reinvented Chinese medicine to cope with the challenge of modern biomedicine.39 The Song transformation of Chinese medicine is clearly critical, yet the active involvement of the state in medicine is already discernable in the earlier days of the Sui and Tang dynasties. Ending the political division of the preceding three centuries, these unified empires established new policies and legal codes in the seventh and eighth centuries to regulate medical practice and punish poisoners who were accused of witchcraft and menacing the stability of the state. They also sponsored the production of medical texts to standardize and circulate pharmaceutical knowledge. Although state engagement in medicine during the Sui and Tang periods occurred on a smaller scale and via different mechanisms—manuscripts, rather than printed texts, were still the dominant medium of transmitting knowledge—it anticipated the governmental regulation of medicine during the Tang-Song transition that has been extensively examined.40
Text and Genre
My emphasis on the materiality of medicines results from a methodological orientation toward a history beyond narratology, discourse analysis, and representations. Yet history is always mediated by texts, and medical history is no exception. What is particularly of note for the period from the Era of Division to the Tang dynasty is that the majority of medical sources in their original form have long been lost; their earliest extant editions were compiled during the Northern Song period (960–1127), driven by the rise of printing and the state’s use of the technology to promulgate medical texts. The prestige of the so-called great canonical works of Chinese medicine, such as The Yellow Emperor’s Inner Classic and Treatise on Cold Damage and Miscellaneous Disorders (Shanghan zabing lun) as we know them today, is due in no small part to the systematic effort of the Song state to elevate the status of these works.41 My study of medieval medical works therefore inevitably relies on these Song compilations and the modern editions based on them.
Before the era of printing, manuscript culture flourished in China.42 Fortunately, an assortment of pre-Song medical manuscripts from a large collection found in Dunhuang and Turfan and dating from the third to the eleventh century has been discovered. Located on the strategic sites of the Silk Road in the far west, Dunhuang (in present-day Gansu) and Turfan (in present-day Xinjiang) were vibrant frontier towns where, during the Tang period, diverse cultures interacted. The manuscripts, most of which are Buddhist scriptures, contain a sizable collection of medical works that are often lost in printed texts.43 Although most of these manuscripts are incomplete and lack contextual information, such as the time of compilation and authorship, they are sources without the editorial influences of later periods and are therefore crucial to the study of medical culture in medieval China. Moreover, in contrast to texts produced at the imperial center, these manuscripts carry regional features that reveal the concerns of local actors. They are thus excellent materials for exploring local medical practices.
Among the pre-Song medical sources, two genres are particularly important to my investigation of medicines. The first is the literature of materia medica (bencao), which provides detailed entries on drugs, each with its properties, morphology, sources of supply, medical uses, and other categories. The genre originated during the Han dynasty and persisted throughout imperial China.44 Importantly, the writing of materia medica followed a commentary tradition; that is, later works faithfully preserved the core text formed in the Han period and added, over time, layers of commentaries at the end of each drug entry. This particular structure demonstrates the importance of textual authority in the making of new knowledge of drugs. The second genre is formula books (fangshu), which contain a large number of medical formulas usually organized by the types of illness they treat. Compared to the materia medica literature, this genre has neither central text to build on nor commentary tradition to adhere to; it is rather an eclectic assembly of remedies culled from diverse sources. Both genres discuss medicines extensively, but with different epistemic orientations, to borrow a concept developed by the historian of medicine Gianna Pomata.45 The former manifests the mentality of canon-building and seeks to establish authority and order, whereas the latter speaks more to the production of empirical knowledge that links to medical practice.
Two examples from the seventh century display the difference clearly. The production of the first government-commissioned pharmacological work, Newly Revised Materia Medica (Xinxiu bencao, 659), exhibited the state’s ambition to standardize pharmaceutical knowledge and exalt the grandeur of the empire, while the personal compilation of Sun Simiao’s formula book Essential Formulas Worth a Thousand in Gold for Emergencies (Beiji qianjin yaofang, 650s; hereafter Essential Formulas) revealed the physician’s project of confirming the efficacy of remedies based on his own experience. The two texts thus generated different types of knowledge with specific political and social values. Yet the epistemic distinction between the two genres is by no means absolute: the commentary section of a materia medica text could contain rich empirical information, just as a formula book could be a scholarly project amassing past wisdom and showcasing erudition.46 Therefore, we must be sensitive to the epistemic variations within a medical genre contingent on the historical condition.
Medicines and the Body
Beyond treating illness, medicines in medieval China also aimed to enhance life. The ultimate goal of the latter pursuit was to evade death altogether (figure I.1), a quest our modern eyes might view as a religious endeavor. Scholars have emphasized the “Daoist” element in classical Chinese pharmacy, since drugs prescribed for nourishing the body also appear in Daoist scriptures.47 In particular, a number of toxic minerals were frequently used in Daoist alchemical practices that sought to promote transcendence and escape death. Poisons could be numinous substances that triggered the transformation of the body into higher states of being.
How do we make sense of the “religious” elements in classical Chinese medicine? Rather than treating “medicine” and “religion” as universal categories, it is important to recognize their historical roots in post-Enlightenment Europe and acknowledge their limitations when applied to other times and places.48 If we refrain from an anachronistic approach, it is hard to separate “medicine” from “religion” at the conceptual, textual, or sociological level in premodern societies. Previous scholarship has amply demonstrated that in medieval and early modern Europe, scientific knowledge was interwoven with religious aspirations in the domains of astrology, alchemy, and medicine.49 This was also the case in medieval China, where medicine operated in a world suffused with Buddhist, Daoist, and various folk religious activities. At the conceptual level, the effort to combat illness and pursue immortality formed a continuum in classical Chinese pharmacology. At the level of practice, healers in medieval China incorporated a constellation of methods (drug therapy, talismanic healing, meditation, incantation, etc.) that defied the clear boundary between “medicine” and “religion.” Like two sides of the same coin, they were inseparable in premodern Chinese culture.50
A crucial issue in the study of religious healing in premodern China is how medicines interacted with the body. Scholarship on the history of the body has yielded critical insights into the profound differences in the perception and experience of the body in various medical and religious traditions.51 Moreover, recent studies of material culture in both Buddhism and Daoism have demonstrated the abundant use of objects in religious practice and the entwined relationship between the spiritual and the material.52 What has been barely explored, however, is the interaction between the body and things, especially the effect of a given medicine on the body and how such an effect shaped the understanding of the medicine and of the illness it treated.53 Since toxic substances often induced violent sensations, they offer a window through which to examine the intimate relationship between the ingestion of medicines and the transformation of the body, a theme particularly prominent in Daoist alchemy. Although the interpretations of these sensations could be varied and counterintuitive, they expressed the irreducible physicality of the body, a body that endured pain and even death.54 The tension between physical anguish and spiritual elevation was precisely what was at stake in the case of elixir poisoning in Chinese alchemy. Examination of these experiences and their diverse explanations illuminates the vital link between the sensations of the body and the knowledge of medicines.
Healing with Poisons is divided into three parts. Parts I and II follow a chronological order, focusing on the therapeutic use of poisons. Specifically, part I explores the prominence of poisons in Chinese pharmacy during its foundational period from the Han dynasty to the Era of Division, investigating the paradoxical meaning of du and the diverse techniques that transformed poisons into medicines. Part II examines the changing landscape of Chinese pharmacy in the Sui and early Tang dynasties, inspecting the heightened concern about poisoning and witchcraft in political circles, the state patronage of producing and promulgating pharmaceutical knowledge, and physicians’ keen interest in applying such knowledge in practice. Part III, spanning the entire period under study, examines poisons in life enhancement. It moves our story of poisons beyond the realm of curing sickness, scrutinizing their extraordinary power to illuminate the mind and prolong life, in the case of Five-Stone Powder, and to transform the body and confer immortality in alchemy.
Finally, a few words on the translation of du. No English expression perfectly captures the paradoxical meaning of du. A word like “poisomedicine” might do the job, but creating an awkward neologism is hardly a good choice for translation. Just as the identity of a medicine changed with the context of its formulation and usage, the meaning of du varied with the specific text in which it appeared. A medicine in classical Chinese pharmacy, then, was something of a mutable character and transformative potential. Because of du’s versatile meanings, in what follows I translate it differently depending on the context. I also leave du untranslated in materia medica texts to underscore its ambivalent meaning. In cases where the positive sense of healing is evident, I translate it as “potent” or “potency” to connote the therapeutic power of a medicine. In cases where the negative sense of harm is clear, I translate it as “poisonous” or “poisoning.” In addition, I often use the word “poisons” as shorthand for medicines that possess du in Chinese pharmacy. This particular way of using the word, I must clarify, does not imply the absolute harmfulness of a substance but rather spotlights the inherent tension between poison and medicine, which is precisely what we are now setting out to explore.